These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Broken Base: On one side, people praise it for bringing back memories of Mister Rogers', or just praise it as a standalone series. On the other side, people pan the Adobe Flash (and the computer generated animation, if they've actually seen an episode) and the series for being too cartoonish and not staying true to Rogers.
Heartwarming In Hindsight: In one week of "Mr. Rogers" episodes, Prince Tuesday is left in the care of babysitters, and has to be helped through it. Now, he's been able to pay it forward.
Never Trust a Trailer: The original promos for the series did NOT make it clear that the series would mostly be animated in CGI.
Periphery Demographic: It's becoming fairly obvious that the show has a growing periphery demographic consisting of those who remember the original Mister Rogers fondly and enjoy seeing the characters again in this new show, parents who have watched the show with their children and found it charming, and adult fans who either didn't really know the original Mister Rogers show or were only passingly familiar with it, but like the new show. Those who liked Blue's Clues and are aware that the show is being made by the company formed by its creators (and others that are aware it's also made by the folks that brought us Super Why!) may be part of the general mix as well.
Some Anvils Need to Be Dropped: The episodes on voting remind us that we should try to find something good about alternatives when we don't get what we want. It's important for everybody.
They Changed It, Now It Sucks: Those who remember Mister Rogers and don't like this show generally believe this. Reasons range from "children need to see real people instead of cartoons" and "it's missing that warmth and magic" to "it's too cartoonish and hyper" and "this is blasphemy! Mister Rogers must be rolling in his grave!"